Ladders are well-known and useful implements. There are various types of ladders, including step ladders and extension ladders. While ladders are generally useful and convenient, they do suffer the disadvantage of being somewhat unstable, tending to tip laterally if a lateral force is applied thereto, particularly when the force is applied above the center of gravity of the ladder. As used herein, the term "lateral" refers to a direction or motion which is substantially parallel to the rungs or steps of a ladder. For example, a lateral adjustment would be one which is substantially parallel to the rungs or steps of the ladder. Also, ladders can possess a lack of transverse stability under certain circumstances. The term "transverse" herein refers to a direction which is substantially perpendicular to the rungs or steps of a ladder.
The present invention is directed to a method and apparatus for stabilizing a ladder, to minimize the unstableness which is characteristic of most commercial and non-commercial ladders.
Preferably, a ladder stabilizer will accommodate an uneven ground surface and will also allow an individual using a ladder to lean in various directions and move about without causing the ladder to sway or slip. It is also preferable that a ladder stabilizer be fully adjustable to accommodate other conditions such as the presence of a wall, tree, etc., while still rigidly and safely bracing the ladder.
Prior art ladder stabilizers generally do not provide sufficient adjustability and stability and none of the prior art teaches the "self-adjusting" feature of the present invention.
Also, the prior art teaches a number of embodiments which require modification of the ladder such as U.S. patent No. 4,964,488 to Stewart which requires that braces be attached to the ladder and are not self-adjusting. The U.S. patent No. 4,926,968 also teaches braces which must be attached by boring holes in the ladder to mate with the braces and are not self-adjusting. Again, U.S. patent No. 4,872,529 teaches braces which while being telescopic must be attached to a modified ladder and is not self-adjusting.
The ladder stabilizer of the present invention is directed to the shortcomings of the prior art ladder stabilizers. In particular, it provides removably attachable means which requires no alteration of the ladder and is self-adjusting when the ladder is "rocked" laterally.